Squares in Matrix

using System;
using System.Linq;

namespace Squares_in_Matrix
{
    class Program
    {
        static void Main()
        {
            var nxm = Console.ReadLine()
                .Split()
                .Select(int.Parse)
                .ToArray();
            var rows = nxm[0];
            var cols = nxm[1];
            var count = 0;
            if (rows >= 2 && cols >= 2)
            {
                var matrix = new char[rows, cols];
                for (int row = 0; row < rows; row++)
                {
                    var input = Console.ReadLine()
                        .Split(' ',StringSplitOptions.RemoveEmptyEntries)
                        .Select(char.Parse)
                        .ToArray();
                    for (int col = 0; col < cols; col++)
                    {
                        matrix[row, col] = input[col];
                    }
                }
                for (int row = 0; row < rows - 1; row++)
                {
                    for (int col = 0; col < cols - 1; col++)
                    {
                        if (matrix[row, col] == matrix[row, col + 1] &&
                            matrix[row, col] == matrix[row + 1, col + 1] &&
                            matrix[row, col] == matrix[row + 1, col])
                        {
                            count++;
                        }
                    }
                }
            }
            Console.WriteLine(count);
        }
    }
}